Piston rings



Feb. 11, 1958 PISTON RINGS s Sheets-Sheet 1 Original Filed Dec. 23. 1952 m m 4 m M a WWW rm. m m w .A E

INVENTOR V/cm/e fiz/rwmm/v "l'liiiiiflilflilli Feb. 11, 1958 ZAHOD'AK'N 2,823,086

PISTON RINGS 3 Sheets-Sheet 2 Original Filed Dec. 23. 1952 V. F. ZAHODIAKIN PISTON RINGS Feb. 11, 1958 Original Filed Deb. 23. 1952 '3 Sheets-Sheet 3 ATTORN EY PISTON RINGS Victor F. Zahodiakin, Summit, N. J.

Original application December 23, 1952, Serial No. 327,470, now Patent No. 2,707,661, dated May 3, 195 5. Divided and this application February 2, 1955, Serial No. 485,724

Claims. (Cl. 309-44) The present invention, division of application S. N. 327,470, filed December 23, 1952, now Patent Number 2,707,661, relates to flexible rings, and more particularly, to piston rings which are used for oil control or which are used to prevent the escape past the piston of gas and compression from the combustion chamber of an internal combustion engine.

Piston rings must be extremely flexible so that intimate contact between the ring and cylinder wall will be assured. Thus where the purpose of the ring is to scrape excessive oil from the cylinder wall, the scraping edge of the ring must closely follow the contours of the cylinder wall. These contours will vary, due to distortion, as the temperature of the cylinder varies and as wear occurs during the operation of the engine. Compression rings must also have intimate contact with the cylinder wall around the periphery of the ring in order to prevent the escape of gases and pressure from the combination chamber during the operation of the engine.

' Therefore the principal object of my invention is to provide a piston ring of improved flexibility without sacrifice of strength.

A further object of my invention is to provide a piston ring of improved flexibility having improved means to uniformly bias the periphery of the ring into intimate contact with the cylinder wall.

' Yet another object of the invention is to provide for predetermined pliability of the ring, and more specifically, to provide a perforate scallop wherein the material thickness of the scallop governs the flexibility.

- Another object of the invention is to provide a ring having segmental contact with the cylinder wall and to apply pressure at a .part radially outward beyond the innermost part of the ring.

1 'A' still further object of the invention is to provide a ring which is economical to manufacture and assemble.

The above objects, and other objects which will become apparent as the description proceeds, are accomplished by providing a ring comprised of two spaced annular members having circumferentially spaced apertures therein axially parallel to the ring axis, and means to uniformly bias the outer periphery of the annular members into engagement with the cylinder wall.

The following description will be best understood by reference to the accompanying drawings of preferred embodiments of my invention wherein like numerals of reference refer to similar parts thoughout the several figures of the drawings in which:

' Fig. 1 is an elevational view of a pistonring constructed in accordance with my invention;

Fig. 2 is a plan view of the ring of Fig. 1;

V Fig. 3 is a fragmentary vertical sectional view of a piston and cylinder of an internal combustion engine showing the use of compression and oil-control rings;

- Fig. 4 is a fragmentary cut-away cross-sectional view of a piston andcylinder and showing a portion of an oil-control ring of my invention in plan;

States Patent 0 "ice Fig. 5 is a sectional view through the piston ring of Fig. 1 taken along line V-V of Fig. 4;

Fig. 6 is an exploded side view of the elements of the piston ring of Fig. 1 showing the elements in position for assembly;

Fig. 7 is a sectional view similar to Fig. 4 and showing a modified construction of a piston ring constructed according to my invention;

Fig. 8 is a cross-section on line VIII-VIII of Fig. 7;

Fig. 9 is a sectional plan similar to Figs. 4 and 7 and taken on line IX-IX of Fig. 3, showing a portion of a compression ring of my invention;

Fig. 10 is an elevational view similar to Fig. 1 and showing a modified construction of oil-control ring;

Fig. 11 is a plan of the ring of Fig. 10;

Fig. 12 is a perspective of a portion of the resilient spacer of the ring of Fig. 10 and Fig. 11;

Fig. 13 is a fragmentary perspective view of one of the ring members according to the modified construction of Figs. 10 and 11;

Fig. 14 is an enlarged sectional plan similar to Figs. 4, 7 and 9 showing a portion of the ring of Figs. 10 and 11; and

Fig. 15 is a cross-section of piston, cylinder and rings on line XVXV of Fig. 14.

The piston ring of Fig. 1 is especially adapted for use as an oil-control ring. As illustrated in Fig. 3, pistons are generally provided with a plurality of rings which are set in individual grooves in the periphery of the piston to retain compression and properly control the lubrication of the cylinder bores. The primary function of the lowermost ring, termed an oil-control ring, is to scrape the excess oil from the cylinder wall and return it to the crankcase or other reservoir while the primary function of the other rings is to prevent the escape of gas and pressure from the combustion chamber. Thus the piston 20 of Fig. 3 is provided with compression rings 21 and an oil control ring 22. Each ring is set in a substantially horizontal groove 23 of rectangular cross-section in skirt 24 of the piston 20. The oil control ring 22 is lowermost and its groove 23 is connected to the oil reservoir by a series of drain outlets 26 runningfrom the lowermost groove 23 through the skirt of the piston.

The oil control ring 22, constructed according to my invention, is comprised generally of two annular spaced members 27 separated by a resilient spacer 28, as best illustrated in Figs. 5 and 6. The outer peripheral surfaces 29 of the annular members 27 are adapted to scrape the excess of oil from the wall 31 of the cylinder in which the piston operates. These annular members 27 may be conveniently formed of a high carbon steel ribbon and after hardening will provide long-wearing scraping surfaces.

The flexibility of each annular member is increased by a series of apertures 32, preferably circular, although other desired forms may be used. Said apertures are spaced one from another along each annular member 27 on a circle concentric with the annular member between the inner and outer peripheries thereof. The apertures 32 may be termed axial apertures, since their axes are parallel to the axes of the annular members. Slits 33, preferably radial, run from the outer periphery of each annular member 27 to the aperture 32. Each annular member 27 has a slit 27 to permit convenient assembly and allow expansion and contraction of the ring during operation of the engine.

Thus the oil scraping surface 29 is divided into a plurality of segments 34 capable of relative'movement with respect to each other, thereby providing a ring which is flexible in its own plane and which has a segmental oil scraping edge that can follow irregularities in the cylinder wall.

The flexibility of each annular member 27 may be further increased and the pliability predetermined, according to my invention, by scalloping the inner periphery of the member. Thus midway between each aperture 32 is a radial notch 36 cut in the inner periphery of the annular member. Adjacent notches are joined by a scallop 37 the center of curvature of which is concentric with the aperture 32 between the notches. Thus every point on the periphery of the scallop 37 is equidistant from the aperture 32 concentric with the particular scallop. The constant thickness of material between the apertures and the inner periphery of the annular member imparts desired uniform pliability to the member. Preferably the radial notches 36 terminate on a circle with a radius to meet the radius of scallops 37.

The annular members 27 are spaced apart by a resilient spacer 28. The spacer 28 of Figs. 1 to 8 has tongues 39 extending from each edge thereof which fit into the apertures 32 of the annular members 27. Preferably, the tongues on each edge are aligned so that the apertures 32 of the two annular members will be opposite each other, as shown, for instance, in Fig. 5 of the drawing. The spacer 28 is of generally wavy character and as one example illustrated by Fig. 4, considering an increment of length from one tongue 39 to the next, is approximately 2 or N-shaped, and in Figs. 7 and 14 is approximately M or Vi -shaped. The structure therefore provides humps or loops 40 of the Z, N, M or W formation extending inwardly beyond the inner periphery of the annular member and adapted to bear against the bottom of piston groove 23 in which the ring is seated in use. The biasing force of the spacer bearing against the bottom of the groove 23 will be transmitted by the tongues 39 to the annular members 27, as shown on Fig. 4, and will force them radially outward into intimate engagement with the cylinder wall 31. The tongues 39 are transversely symmetric to and intercept the same radius of the annular member 27 as the corresponding slit 33, as shown in Fig. 4, so ithe force applied by the tongue will be uniform in its action on the segments of the member 27 bordered by the particular slit 33. The outwardly projecting loops 40A are positioned closer to the outer periphery of the member 27 than to the inner periphery of member 27 for the purpose of vertical support of the members 27.

Fig. 7 illustrates a modified form of an oil-control ring constructed in accordance with my invention. The flexibility of each annular member 27 of the piston ring is increased by slots 41 spaced one from each other in a circular series along the annular member 27. A radial slit 33 runs from the center of slot 41 to the outer periphery of the annular member dividing the oil scraping surface 29 into aplurality of segments 34 as in the case of the ring of Figs. l6. Between each pair of adjacent slots 41 is an aperture 42 which has a radial slit 43 running from the aperture to the inner periphery of the annular member 27. The inner periphery is thus divided into a plurality of segments which enables the ring to flex inwardly as well as outwardly from its normal position wherein the sides of each slit are touching.

The slots 41 in the two annular members are aligned in a direction parallel to the axis opposite each other by tongues 44 which lit the slots 41. The tongues 44 are joined by a wavy resilient spacer shown this time as approximately W-shape and having tongues 44 which are an integral part of the spacer. Two humps 45 of the W-shaped tension spacer extend beyond the inner periphery of the annular members and are adapted to bear against the bottom of the groove 23 to bias the annular members outwardly into engagement with the cylinder Wall. As in the first described embodiment, the tongues in each slot 41 exent equal pressures on the two segments against which the tongue bears and therefore provided absolutely uniform radial pressure. The elongated form of slot 41 greatly facilitates the flexibility of the ring.

The embodiment of my invention shown in Fig. 9 is intended primarily for use as a compression ring. The compression ring is comprised of two annular members 27 which are back to back. Each annular member has apertures 32 therethrough in an axial direction spaced one from each other along the member. The apertures lie on a circle concentric with the annular member. As in the first embodiment, between adjacent apertures is a radial notch 36 running outwardly from the inner periphery to increase the flexibility of the member and adjacent notches 36 are joined by a concentric scallop 37 providing for pliability of the member.

Each annular member 27 also has a slit 46 running from each aperture 32 to the outer periphery of the member. The outer periphery is thus divided into a plurality of segments. The slits 46 differ from the slits 33 of the previous embodiment in that each slit makes an acute angle with a radius of the annular member 27 on which the center of its corresponding aperture lies. When the compression ring is assembled, the apertures 32 in the juxtaposed members are aligned or register with each other, but the slits 46 of the bottom annular member 27 are preferably offset from the slits 46 of the upper annular member 27 so that the gases in the combustion chamber are not allowed to escape which may occur if corresponding slits 46 in the top and bottom annular member were in a common plane. More specifically, the bottom member 27 is provided with sliits 46 which make a different angle with their corresponding radii of the annular members than do the slits 46 of the upper member, both angles being in the same direction, for instance clockwise from the radius. As noted above, the corresponding radius for a particular slit 46 is the radius of the annular member which passes through the center of the aperture 32 into which the slit 46 opens. Thus in the preferred embodiment, the slits 46 of the upper annular member 27 make an angle of approximately with its corresponding radius, while those. of the lower annular membermake an angle of approximately 200.

In order to bias the annular members 27 of the com: pression ring outwardly into engagement with the cylinder wall, a sinuous spring 47 is provided which is comprised of a series of inward loops 48 the adjacent loops of which are joined by a smaller outward loop 49. The outward loop. 49 fits between scallops 37 of the annular members 27which are in alignment and the larger inward loops 48 bear against the bottom of the groove 23 in which the ring is seated.

While the foregoing description has referred to tongues on the spacer engaging in recesses in the ring members, this relationship may be reversed and tongues on the membersmay engage in recesses or declivities in the spacers, this relationship being more especially illustrated in Figs. 10. to 15, inclusive. Here, as in the preceding disclosures, the ring iscomprised of two ring members 27 spaced in parallelism by an intervening tension spacer 28. The outer periphery 29 of each member constitutes an edge for engagement with the cylinder wall 31. Again, a circular series of apertures 32 are provided in the members with the corresponding apertures, one overlying another, being aligned on axes parallel to the axis of the ring. Slits 33 extend in radial directions from each aperture to the outer periphery of the member, and thus the member is divided into a circular series of segments 34 juxtaposed ends of which are in abutting relationship to each other to constitute a substantially continuous edge surface. The segments are successively integral with each other by a continuity of the metal from segment to segment around the apertures next the inner peripheral. part of said members, by virtute of scallops 37.

The scallops 37 are spaced from each other at thebas'al part of their valleys, and the metal thereat is bent perpendicular to the plane of the member to provide a protruding tongue 54 thereat, the tongues being in a cylindrical series. The tongues of the upper member project downwardly whereas the tongues of the lower member project upwardly, and are in pairs projecting axially toward each other. From a manufacturing standpoint, it is easier to provide these tongues 39 and 44 on the spacer. Furthermore, the fabrication of the spacer and assembly of the ring are simplified by the presently described construc tion of tongues on the members.

It is now appropriate to point out that the top and bottom edges of the spacer each lie in a plane common with the general plane of the juxtaposed face of the respective member. The circular configuration of the spacer provides a series of successive loops, of which there are long humps or loops 45 projecting radially inwardly of the ring and intervening short humps or loops 55, the hollow of which engage against the pairs of tongues 54 of the members. By virtue of the flexibility of the members and the resiliency of the spacer, the segments are individually pressed toward the cylinder wall and will follow the irregularities thereof to maintain sealing contact therewith. Oil passages 56 may be appropriately located in the spacer, for instance, at the top and bottom edges there-of, as shown.

I claim:

1. A piston compression ring comprising two annular members one on top of the other, each of said members having apertures therein spaced one from another along said members on a circle concentric with said member, each said member having notches running to the inner periphery thereof, one notch being between each pair of adjacent apertures, a scallop joining adjacent notches and concentric with the aperture embraced by said scallop, said members having slits running from each of said apertures to the outer periphery of the member, the slits of one of said members being offset from the slits of the other of said members, and biasing means in part projecting into said notches and bearing against said scallops to bias said members outwardly.

2. A piston ring comprising parallel members each having an inner periphery with scallops and valleys in radial directions, and biasing means disposed in part between said members and in part projecting radially inward thereof, said members having slits each angularly disposed with reference to a radial plane of the members that intersects the inward end of the respective slit of one member contiguous to a slit of the other member constituting a pair of slits and with one slit of each pair diverging at one side of said plane and the other slit of the pair diverging from the other side of said plane whereby said slits are out of registration, and biasing means having engagement at said valleys for application of outward force on the members by the biasing means thereby tending to expand the member and open the out of registration slits thereof.

3. A piston compression ring comprising parallel members each having a single radial split for enabling the members to expand and contract in use, said members being one on top of the other, each of said members having apertures therein spaced one from another along said members on a circle concentric with said member, each said member having notches running to the inner periphery thereof, one notch being between each pair of adjacent apertures, a scallop joining adjacent notches and concentric with the aperture embraced by said scallop, said members having slits running from each of said apertures to the outer periphery of the member, and biasing means in part projecting into said notches and bearing against said scallops to bias said members outwardly.

4. A piston compression ring comprising two annular split members one on top of the other, each of said members having apertures therein spaced one from another along said members on a circle in relation to said member, the apertures in one member being coaxial in pairs with apertures of the other member and each said memher having notches running to the inner periphery thereof, one notch being between each pair of adjacent apertures, a scallop joining adjacent notches and with the aperture embraced by said scallop, said members having slits running from each of said apertures to the outer periphery of the member, the slits of one of said members being offset from the slits of the other of said members and with the slits of one member each angularly disposed at one side of a respective plane radial both to the member and aperture and with the slits of the other member each angularly disposed at the other side of said respective plane, and biasing means in part projecting into said notches and bearing against said scallops to bias said members outwardly.

5. A piston compression ring comprising two annular split members one on top of the other, each of said members having apertures therein spaced from one another along said members on a circle concentric with said member, each said member having notches running to the innor periphery thereof, one notch being between each pair of adjacent apertures, a scallop joining adjacent notches and concentric with the aperture embraced by said scallop, said members having slits running from each of said apertures to the outer periphery of the member and said outer periphery of said members being divided into a plurality of segments, the sides next said slits of successive segments abutting one against the other, the slits of one of said members being offset from the slits of the other of said members and each disposed at one side of a respective plane radial to both the member and aperture and with the slits of the other member each angularly disposed at the other side of said respective plane, and biasing means adapted to bear against said scallops to bias said members outwardly.

References Cited in the file of this patent UNITED STATES PATENTS 2,311,727 Bowers Feb. 23, 1943 2,345,176 Bowers Mar. 28, 1944 2,387,084 McFall et al Oct. 16, 1945 2,560,667 Stevenson July 17, 1951 2,560,668 Stevenson July 17, 1951 FOREIGN PATENTS 123,352 Great Britain Feb. 27, 1919 

